For Level 1 applications requiring ATEX/IECEx Zone 1 or 21, protection use the XRB1 or XRB2 isolator in your control cabinet which permits the use of intrinsically safe wiring instead of explosion-proof conduit or glands. The XR85 can also be used in UL Class I Div 1 & Zone 0 applications using the XRB2 Isolator.

In This Section

In This Section

ATEX is a directive used worldwide for equipment, including encoders, to be used around or in explosive atmospheres. ATEX certified equipment is NOT necessarily interchangeable with US-based UL Class/Division or Class/Zone rated equipment, nor IECEx rated equipment. ATEX is an alternative and different system. Review our full line of Avtron Explosion Protected, ATEX certified encoders, including M6, M6C and XR models.

A machined flange or elevated/recessed face provided on motors for mounting accessories. Typically provided on the drive end for gearbox/load mounting, C-faces may also be provided on the non-drive end for mounting encoders, brakes, and other accessories.

A Cam Screw Rotor eliminates the problems associated with slipping rotors of other types; it uses two cam (eccentric) head screws. The screws are preloaded into the rotor; simply rotate them (approximately 90°-180°) to fully engage the shaft (4-6 ft-lbs) using a standard hex (Allen) wrench. Cam screw rotors are available on AV850, AV56, AV67, AV85, and AV115 THIN-LINE II™ encoders. Cam Screw Rotor Patent # 7,485,997. Cam Screw Rotor™ is a trademark of Avtron.

Also known as contaminants, such as water, dirt, dust, oil, and other compounds which enter an encoder through seal failure and can cause optical errors. If the contamination is abrasive, it can also cause bearing failures in the encoder. Modular encoders are very resistant to contamination as they use magnetoresistive sensors and have no bearings.

A device which indicates position and speed via a set of digital outputs. Incremental encoders output quadrature (A Quad B) signals, and may add a marker pulse once per revolution. Absolute encoders typically indicate position via a digital message, a set of parallel outputs, or analog values.

Also known as Flameproof, explosion protected equipment has additional protection/safety enhancements for use in explosive atmospheres. Explosion Protected devices maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison, Intrinsically Safe devices may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Explosion Protected encoders.

A Flange Adapter provides the NEMA 56C motor mounting face and properly locates the encoder shaft. The encoder shaft and motor shaft are then connected using a flexible coupling. (Drawing "A") Often flange adapters can be eliminated by directly mounting a modular encoder such as an Avtron AV125, AV850, AV56, AV67, AV85, AV115 unit on the motor flange. (Drawing "B")

Is a system designed to improve equipment safety by limiting spark energy values in equipment used in hazardous areas. Intrinsic Safety is a different system of protection than Explosion Proof or Flameproof. Many Explosion Proof and Flameproof encoders can be replaced with Intrinsically Safe encoders, provided the installation instructions are followed correctly and the system is compliant with the approved installation drawing. Intrinsically safe Avtron XR encoders are available in Level 1 protection and Level 2 protection.

Magnetic and magnetoresistive encoders typically use a magnetized rotor with north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions, and these are the counts or pulses generated by the encoder. Magnetic encoders withstand dirt, dust, water, and temperature changes far better than optical encoders.

Modular Encoders mount to a machined C-face or flange adapter on the motor (drive or non-drive end). Modular encoders consist of a rotor that mounts on the shaft, and a stator that bolts to the motor frame. Modular encoders are very rugged, and Avtron encoders feature Wide-Gap sensors to avoid complex shimming or fitting to the motor. Modular C-face encoders are typically used on DC motors; but some AC motors, such as Rockwell’s RPM III AC and Marathon’s Blue and Black Max motors, have C-faces standard on the non-drive end for mounting an encoder.

An Optical Disk is typically a glass, metal, or plastic disk with fine lines or slots etched around the perimeter that interrupt the beam of light from the light source to an optical sensor. Optical disks can be quite fragile. Avtron uses only shatterproof optical disks with Wide-Gap technology.

Pulses Per Revolution. Most Avtron encoders output quadrature pulses, with four times as many lines as pulses. Often lines can be counted in the drive/speed controller for higher resolution applications.

When the rotating disk in an encoder contacts the sensor (optical or magnetic/magnetoresistive), it damages or destroys the sensor. Sensor crashes can be caused by excessive vibration, shaft runout, or alignment problems in encoder mounting. Avtron encoders feature Wide-Gap technology to eliminate sensor crashes.

Often, to produce precise stub shaft, modular encoder, or foot mount installation, shims are placed between the two items to be aligned. Avtron encoders are designed to eliminate the need for shimming. Many competitors’ modular encoders still require shimming for proper operation.

Avtron encoders use special optical sensors and magnetoresistive sensors, combined with proprietary circuit designs to allow the sensor to be located much farther from the magnetic rotor or optical disk. This eliminates sensor crashes and makes mounting easy and forgiving of mechanical variation.